1. Field of the Invention
The invention relates to a control system for a vehicle including a powertrain in which an engine and a transmission are coupled to each other via a damper device and, more particularly, to a system that controls a rotation speed or operating point of the engine.
2. Description of Related Art
A damper device is arranged on an output side of an engine for the purpose of improving a ride comfort of a vehicle or reducing noise by suppressing fluctuations in torque that is transmitted to drive wheels. Japanese Patent Application Publication No. 2013-113348 (JP 2013-113348 A) describes a torsional vibration reduction device having the following configuration. A spring damper is arranged between an output shaft of an engine and a torque converter, and a pendulum damper is connected to an output-side (driven-side) member of the spring damper.
In the system described in JP 2013-113348 A, because the pendulum damper is coupled to the driven-side member of the spring damper, the overall vibration damping characteristic of the torsional vibration reduction device may change depending on an inertial mass that is exerted on the pendulum damper. That is, the pendulum damper includes pendulums (or rolling elements) as inertial mass bodies; however, the mass of a rotary member that is coupled to the pendulum damper functions as an inertial mass body depending on the manner of coupling the rotary member to the pendulum damper. Conventionally, not focusing on the characteristics of such a pendulum damper or dynamic damper, the overall vibration damping characteristics of the torsional vibration reduction device including the spring damper and the pendulum damper are not effectively utilized.